scholarly journals A Novel Check-List Strategy to Evaluate the Potential of Operational Improvements in Wastewater Treatment Plants

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5005
Author(s):  
Vojtěch Zejda ◽  
Vítězslav Máša ◽  
Šárka Václavková ◽  
Pavel Skryja

With increasing demands for cleaning and purification of water, wastewater treatment plants (WWTP) require their most efficient operation. The operators are thus obliged to constantly review the efficiency of the processing units and technological equipment of WWTPs and seek opportunities for improvements. To increase the efficiency of particular equipment, the important parameters to be used for the intensification must be correctly selected. A common WWTP consists of different types of processing units, where the basic parameters can be changed to achieve the highest efficiency (i.e., maximum output with minimum energy consumption) in the WWTP. However, due to many possible technologies in the wastewater treatment process, the combinations of processing units can be complex. In such cases, the efficiency assessment can be misleading if only basic parameters were accessed. Moreover, single-unit intensification can potentially improve the efficiency of the unit itself but cannot guarantee full process improvement. This can be due to negative causal effects in the downstream due to that unit intensification. This work reviews of key parameters at five selected pieces of WWTP equipment (inlet pump station, airlift pump, primary sedimentation tank, aeration chamber, and mixing of anaerobic digester) to demonstrate the correct selection of all affected parameters for the efficiency assessment. In the context of the whole WWTP process, it is necessary to take into account several other parameters to evaluate the efficiency of the equipment. Finally, a methodology for assessing the significance of the identified parameters is proposed. This methodology is effectively applied and demonstrated in the WWTP case study.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9325
Author(s):  
Katarzyna Jaromin-Gleń ◽  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Yaroslav Danko ◽  
Grzegorz Łagód ◽  
...  

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2 emissions is still unknown. The emission of CO2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.


2020 ◽  
Vol 249 ◽  
pp. 119327 ◽  
Author(s):  
Sadegh Alizadeh ◽  
Hamid Zafari-koloukhi ◽  
Fatemeh Rostami ◽  
Masoud Rouhbakhsh ◽  
Akram Avami

2004 ◽  
Vol 4 (1) ◽  
pp. 23-33
Author(s):  
H. Ødegaard ◽  
Z. Liao ◽  
E. Melin ◽  
H. Helness

Many cities need to build compact wastewater treatment plants because of lack of land. This paper discusses compact treatment methods. An enhanced primary treatment process based on coarse media filtration is analysed. A high-rate secondary wastewater treatment process has specifically been investigated, consisting of a highly loaded moving bed biofilm reactor directly followed by a coagulation and floc separation step. The objective with this high-rate process is to meet secondary treatment effluent standards at a minimum use of chemicals, minimum sludge production and minimum footprint. It is demonstrated that the biofilm in the bioreactor mainly deals with the soluble organic matter while coagulation deals with the colloidal matter. The bioreactor may, therefore, be designed based on the soluble COD loading only, resulting in a very compact plant when a compact biomass/floc separation reactor (i.e. flotation or direct filtration) is used. The paper reports specifically on the coagulant choice in flotation and filter run time in direct filtration.


2019 ◽  
Vol 11 (23) ◽  
pp. 6658 ◽  
Author(s):  
I-Tae Kim

This study was conducted to secure the sustainability of biogas plants for generating resources from food waste (FW) leachates, which are prohibited from marine dumping and have been obligated to be completely treated on land since 2013 in South Korea. The aim of this study is to reduce the nitrogen load of the treatment process while producing bio-methanol using digested FW leachate diverted into wastewater treatment plants. By using biogas in conditions where methylobacter (M. marinus 88.2%) with strong tolerance to highly chlorinated FW leachate dominated, 3.82 mM of methanol production and 56.1% of total nitrogen (TN) removal were possible. Therefore, the proposed method can contribute to improving the treatment efficiency by accommodating twice the current carried-in FW leachate amount based on TN or by significantly reducing the nitrogen load in the subsequent wastewater treatment process. Moreover, the produced methanol can be an effective alternative for carbon source supply for denitrification in the subsequent process.


2015 ◽  
Vol 809-810 ◽  
pp. 1573-1578
Author(s):  
Casen Panaitescu ◽  
Monica Emanuela Stoica ◽  
Ciner Fehiman

Manufacture of wastewater treatment technologies is an important issue due to the complexity of design parameters and performance. Biological wastewater treatment is a process in which the intensity of oxygen transfer into water is an issue that has been extensively studied but yet insufficiently resolved. The present paper aims to describe an aeration system developed by the author in the laboratory by means of non-conventional technologies, and subsequently implemented in refinery wastewater treatment plants. The aeration system takes the form of modules, which are equipped with a new type of membrane. The analysis of the system performance revealed that oxygen transfer was 62%, specific adsorption of oxygen was 37 % and the specific oxygen transfer was 7%/m. The advantages of this new system are as follows: compared to existing technologies there is a higher rate of oxygen transfer into water; longer life; there are no dead zones in the basin as a result of their location; possibility of operating on separate sections.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1516
Author(s):  
Il Han ◽  
Keunje Yoo

Wastewater treatment plants (WWTPs) have been considered hotspots for the development and dissemination of antibiotic resistance in the environment. Although researchers have reported a significant increase in bioaerosols in WWTPs, the associated bacterial taxa, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) remain relatively unknown. In this study, we have investigated the abundance and occurrences of ARGs and MGEs, as well as the bacterial community compositions in activated sludge (AS), dewatered sludge (DS) and bioaerosols (BA) in a WWTP. In total, 153 ARG subtypes belonging to 19 ARG types were identified by the broad scanning of metagenomic profiles obtained using Illumina HiSeq. The results indicated that the total occurrences and abundances of ARGs in AS and DS samples were significantly higher than those in BA samples (p < 0.05). However, some specific ARG types related to sulfonamide, tetracycline, macrolide resistance were present in relatively high abundance in BA samples. Similar to many other full-scale WWTPs, the Proteobacteria (58%) and Bacteroidetes (18%) phyla were dominant in the AS and DS samples, while the Firmicutes (25%) and Actinobacteria (20%) phyla were the most dominant in the BA samples. Although the abundance of genes related to plasmids and integrons in bioaerosols were two to five times less than those in AS and DS samples, different types of MGEs were observed in BA samples. These results suggest that comprehensive analyses of resistomes in BA are required to better understand the emergence of both ARGs and MGEs in the wastewater treatment process due to the significant increase of scientific attention toward bioaerosols effects.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1071
Author(s):  
Kasjan Paciuszkiewicz ◽  
Michelle Ryan ◽  
Ian A. Wright ◽  
Jason K. Reynolds

The detection and monitoring of illicit drug concentrations in environmental waters is of increasing interest. This study aimed to determine if illicit and regulated compounds, their potential pre-cursors, and metabolites varied in amount discharged into the environment from treated wastewater at different facilities. Water samples were taken from discharge points of four different tertiary wastewater treatment plants discharging directly into the Hawkesbury-Nepean River (Australia) on two different occasions and analysed to determine the concentrations of compounds including: ephedrine, pseudoephedrine, amphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, methamphetamine, cocaine, and benzoylecgonine. Here, we show that detectable levels of illicit drug and metabolites are being emitted on a consistent basis after having persisted through the wastewater treatment process. The concentrations of methamphetamine are in excess of previously reported surface water concentrations. The estimated total load of compounds being discharged on a daily basis is greater than similar sized catchment areas. The results presented here are of concern from both an ecological and human health perspective.


2013 ◽  
Vol 48 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Kerry McPhedran ◽  
Rajesh Seth ◽  
Min Song ◽  
Shaogang Chu ◽  
Robert J. Letcher

Municipal wastewater treatment plants (MWTPs) are impacted by down-the-drain influents of anthropogenic chemicals. These chemicals are in consumer products and include the flame retardant tetrabromobisphenol A (TBBPA) and antimicrobial triclosan (TCS). Characterization of the distribution of TBBPA, TCS and the TBBPA product tribromobisphenol A (tri-BBPA) was determined at five stages along the treatment process of a typical Canadian MWTP facility. Overall, the TCS concentrations for both liquid (influents, primary effluents and final effluents (FEs)) and solid samples (primary and waste activated sludges) were similar to reported ranges in the literature. In contrast to TCS, both TBBPA and tri-BBPA concentrations were scarcely available in the literature. The TBBPA concentrations were within literature ranges for both influents and sludges, while the tri-BBPA sludge concentrations were markedly higher than a single available previous study. Mass balances for TCS, TBBPA and tri-BBPA indicated 7, 9 and 42%, respectively, of each chemical remaining in the FEs. The resultant annual mass loadings into the Detroit River were estimated to be 3.3 kg, 6.57 g, and 21.5 g for TCS, TBBPA and tri-BBPA, respectively.


2017 ◽  
Vol 23 (2) ◽  
pp. 357-367 ◽  
Author(s):  
Yago Lorenzo-Toja ◽  
Ian Vázquez-Rowe ◽  
Desirée Marín-Navarro ◽  
Rosa M. Crujeiras ◽  
María Teresa Moreira ◽  
...  

2014 ◽  
Vol 71 (3) ◽  
pp. 366-372
Author(s):  
Y. K. Zhang ◽  
H. C. Wang ◽  
L. Qi ◽  
G. H. Liu ◽  
Z. J. He ◽  
...  

In wastewater treatment plants (WWTPs), activated sludge is thickened in secondary settling tanks and recycled into the biological reactor to maintain enough biomass for wastewater treatment. Accurately estimating the activated sludge concentration in the lower portion of the secondary clarifiers is of great importance for evaluating and controlling the sludge recycled ratio, ensuring smooth and efficient operation of the WWTP. By dividing the overall activated sludge-thickening curve into a hindered zone and a compression zone, an empirical model describing activated sludge thickening in the compression zone was obtained by empirical regression. This empirical model was developed through experiments conducted using sludge from five WWTPs, and validated by the measured data from a sixth WWTP, which fit the model well (R2 = 0.98, p &lt; 0.001). The model requires application of only one parameter, the sludge volume index (SVI), which is readily incorporated into routine analysis. By combining this model with the conservation of mass equation, an empirical model for compression settling was also developed. Finally, the effects of denitrification and addition of a polymer were also analysed because of their effect on sludge thickening, which can be useful for WWTP operation, e.g., improving wastewater treatment or the proper use of the polymer.


Sign in / Sign up

Export Citation Format

Share Document